Subaru Legacy IV (2008 year). Manual - part 970

PS-42

Pipe Assembly

POWER ASSISTED SYSTEM (POWER STEERING)

C: INSPECTION

Check all disassembled parts for wear, damage or other problems. Repair or replace the defective parts as
necessary.

CAUTION:
Although the surface layer materials of rubber hoses have excellent weathering resistance, heat re-
sistance and resistance for low temperature brittleness, they are likely to be damaged chemically by
brake fluid, battery electrolyte, engine oil and automatic transmission fluid and their service lives are
to be very shortened. Wipe off hoses immediately if any of these come into contact with the hoses.
Since resistances for heat or low temperature brittleness are gradually declining according to time
accumulation of hot or cold conditions for the hoses and their service lives are shortening accord-
ingly, it is necessary to perform careful inspection frequently when the vehicle is used in hot weather
areas, cold weather areas and a driving condition in which many steering operations are required in
short time.
Continuous discharge of the relief valve for 5 seconds or more will reduce the service lives of hoses,
oil pump, fluid, etc., due to over heating.

Part

Maintenance parts

Corrective action

Pipe

• O-ring fitting surface damage
• Nut damage
• Pipe damage

Replace with a new part.

Clamp

• Loose clamps

Replace with a new part.

Hose

• Flare surface damage
• Flare nut damage
• Outer surface cracks
• Outer surface wear
• Clip damage
• End coupling or adapter deformation

Replace with a new part.

Trouble

Possible cause

Corrective action

Pressure hose burst

Excessive holding time of relief status

Instruct customers.

Malfunction of the relief valve

Replace the oil pump.

Poor cold characteristic of fluid

Replace fluid.

Disconnection of the return 
hose

Improper connection

Repair.

Loosening of the clip

Retighten.

Poor cold characteristic of fluid

Replace fluid.

Fluid slightly leaking out of 
hose

Wrong layout, tensioned

Replace the hose.

Excessive play of engine due to deterioration of 
engine mounting rubber

Replace the parts if defective.

Improper stop position of pitching stopper

Replace the parts if defective.

Crack on hose

Excessive holding time of relief status

Replace.
Instruct customers.

Excessive tightening torque for return hose clip

Replace.

Power steering fluid, engine oil, electrolyte adhere 
on the hose surface

Replace.
Be careful during service work.

Too many uses in extremely cold weather

Replace.
Instruct customers.

PS-43

Pipe Assembly

POWER ASSISTED SYSTEM (POWER STEERING)

NOTE:
There are conditions in which a fluid leak is diagnosed, but is not actually leaking. This is because the fluid
spilt during the last maintenance was not completely wiped off. Be sure to wipe off spilt fluid thoroughly after
maintenance.

Fluid leaking area

Possible cause

Corrective action

Leakage from pipe and hose connec-
tions numbered with (1) through (8) in 
the figure

Insufficient tightening of flare nut, adhesion of 
dirt, damage to flare or flare nut or eye bolt

Loosen and retighten. Replace if ineffec-
tive.

Improper installation of hose or clamp

Retighten or replace the clamp.

Damaged O-ring or gasket

Replace the O-ring, gasket pipe or hose 
with new part, if still no improvement, 
replace the gearbox as well.

Leakage from hose (9) through (13) in 
the figure

Crack or damage in hose

Replace with a new part.

Crack or damage in hose hardware

Replace with a new part.

Leakage from surrounding of cast iron 
portion of oil pump, (14) and (15) in 
the figure

Damaged O-ring

Replace the oil pump.

Damaged gasket

Replace the oil pump.

Leakage from oil tank, (16) and (17) in 
the figure

Crack in oil tank

Replace the oil tank.

Leakage from filler neck of (18)

Damaged cap gasket

Replace the cap.

Crack in root of filler neck

Replace the oil tank.

Fluid level too high

Adjust the fluid level.

Leakage from power cylinder of gear-
box area (19) in the figure

Damaged oil seal

Replace the oil seal.

Leakage from (20), (21) in the figure 
and control valve of gearbox

Damaged gasket or oil seal

Replace the problem parts.

Damage in control valve

Replace the control valve.

(10)

(17)

(1)

(13)

(19)

(4)

(2)

(9)

(8)

(7)

(12)

(15)

(14)

(11)

(16)

(18)

(5)

(6)

(20)

(3)

(21)

PS-00805

PS-44

Oil Pump

POWER ASSISTED SYSTEM (POWER STEERING)

7. Oil Pump

A: REMOVAL

1. H4 MODEL

1) Disconnect the ground cable from the battery.
2) Remove the air intake duct. <Ref. to
IN(H4DOTC)-9, REMOVAL, Air Intake Duct.>
<Ref. to IN(H4SO)-8, REMOVAL, Air Intake Duct.>
3) Remove the pulley belt cover.
4) Loosen the belt tension securing bolt and gener-
ator securing bolt, then remove the power steering
pump V-belt.

5) Disconnect the connector from the power steer-
ing pressure switch.
6) Disconnect the pressure hose and suction hose
from the oil pump.

CAUTION:
• Do not allow fluid to come into contact with
the pulley belt.
• To prevent foreign matter from entering the
hose and pipe, cover the open ends with clean
cloth.
• Non-turbo model

• Turbo model

7) Remove the installation bolt of the power steer-
ing pump bracket.

8) Place the oil pump bracket in a vise, and remove
the two bolts from the front side of the oil pump.

CAUTION:
When securing the oil pump bracket in a vise,
hold the oil pump bracket with the least possi-
ble force between two pieces of wood.

9) Remove the bolt from the rear side of oil pump.

(1) Suction hose

(2) Pressure hose

PS-00461

PS-00688

(1)

(2)

(1) Suction hose

(2) Pressure hose

(2)

PS-00459

(1)

PS-00188

PS-00128

PS-45

Oil Pump

POWER ASSISTED SYSTEM (POWER STEERING)

10) Disassemble the oil pump and bracket by in-
serting a flat tip screwdriver as shown in the figure.

2. H6 MODEL

1) Disconnect the ground cable from the battery.
2) Remove the cover of the pulley belt.
3) Remove the V-belts.
4) Remove the power steering pressure switch
connector.
5) Remove the tensioner adjuster.
6) Disconnect the pressure hose and suction hose
from the oil pump.

CAUTION:
• Do not allow fluid to flow from the hose end
and contact the pulley belt.
• To prevent foreign objects from entering the
hose, cover the hose openings with a clean
cloth.

7) Remove the bolts which holds the power steer-
ing pump bracket.

8) Place the oil pump bracket in a vise, and remove
the two bolts from the front side of the oil pump.

CAUTION:
When securing the oil pump bracket in a vice,
hold the oil pump bracket with the least possi-
ble force between two pieces of wood.

9) Remove the bolt from the back side of the oil
pump.

10) Remove the oil pump from the bracket.

(1) Suction hose

(2) Pressure hose

PS-00129

PS-00700

(1)

(2)

PS-00701

PS-00229

PS-00702